Method of fabricating semiconductor devices utilizing in situ passivation of dielectric thin films

Abstract

A capacitor for a semiconductor device is fabricated by a method which reduces the interaction of a capacitor electrode and a dielectric layer in the capacitor. One or more passivation layers are formed at the interface between the dielectric layer and an electrode in the capacitor by exposing the dielectric layer or electrode to a reactive environment during fabrication in order to form a passivation layer thereon prior to forming an overlying dielectric layer or electrode. The passivation layer reduces the diffusion of oxygen from the dielectric layer to the electrode, resulting in reduced current leakage in the capacitor.

What is claimed and desired to be secured by United States Letters Patent is:  
     
       1. A semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a dielectric layer over the first conductive layer;  
       a passivation layer over the dielectric layer wherein said passivation layer constitutes an electrical conductor; and  
       a second conductive layer over the passivation layer.  
     
     
       2. The device of claim  1 , wherein the first conductive layer, the dielectric layer, and the second conductive layer form capacitor elements. 
     
     
       3. The device of claim  1 , wherein the first and second conductive layers are composed of a material selected from the group consisting of polysilicon, titanium nitride, tungsten, molybdenum, tungsten silicide, tantalum, tungsten nitride, Pt, Ru, RuO x , Ir, IrO x , Pt combinations thereof. 
     
     
       4. The device of claim  1 , wherein the dielectric layer is composed of a material selected from the group consisting of silicon nitride, silicon dioxide, tantalum oxide, strontium titanate, and barium strontium titanate. 
     
     
       5. The device of claim  1 , wherein the passivation layer which constitutes an electrical conductor includes a compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6. 
     
     
       6. The device of claim  5 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       7. The device of claim  1 , wherein the passivation layer includes compounds selected from the group consisting of tantalum nitride, tantalum oxynitride, tantalum fluoride, tantalum carbide, and combinations thereof. 
     
     
       8. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a passivation layer over the first conductive layer, wherein said passivation layer constitutes an electrical conductor;  
       a dielectric layer over the passivation layer; and  
       a second conductive layer over the dielectric layer.  
     
     
       9. The capacitor structure of claim  8 , wherein the passivation layer which constitutes an electrical conductor includes a compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6. 
     
     
       10. The capacitor structure of claim  9 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       11. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a first passivation layer over the first conductive layer, the first passivation layer formed by exposing the first conductive layer to a reactive environment;  
       a dielectric layer over the first passivation layer;  
       a second passivation layer over the dielectric layer, the second passivation layer formed by exposing the dielectric layer to the reactive environment; and  
       a second conductive layer over the second passivation layer; wherein at least one of said first and second passivation layers constitutes an electrical conductor.  
     
     
       12. The capacitor structure of claim  1 , wherein the first and second passivation layers include at least one compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X, Y, and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6, and at least one of said first and second passivation layers including said at least one compound constitutes an electrical conductor. 
     
     
       13. The capacitor structure of claim  12 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       14. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a first dielectric layer over the first conductive layer;  
       a passivation layer over the first dielectric layer, wherein said passivation layer constitutes an electrical conductor;  
       a second dielectric layer over the passivation layer; and  
       a second conductive layer over the second dielectric layer.  
     
     
       15. The capacitor structure of claim  14 , wherein the passivation layer which constitutes an electrical conductor includes a compound having a formula selected from the group consisting of M(O) y X z , M(O) y W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6. 
     
     
       16. The capacitor structure of claim  15 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       17. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a first dielectric layer over the first conductive layer;  
       a first passivation layer over the first dielectric layer;  
       a second dielectric layer over the first passivation layer;  
       a second passivation layer over the second dielectric layer; and  
       a second conductive layer over the second passivation layer, wherein at least one of said first and second passivation layers constitutes an electrical conductor.  
     
     
       18. The capacitor structure of claim  17 , wherein the first and second passivation layers include at least one compound having a formula selected from the group consisting of M(O) y X z , M(O) y W n , M x Y y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6, and at least one of said first and second passivation layers including said at least one compound constitutes an electrical conductor. 
     
     
       19. The capacitor structure of claim  18 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       20. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer on a semiconductor substrate;  
       an electrically conductive passivation layer on the first conductive layer, wherein said passivation layer constitutes an electrical conductor;  
       a dielectric layer on the passivation layer; and  
       a second conductive layer on the dielectric layer.  
     
     
       21. The capacitor structure of claim  20 , wherein the passivation layer which constitutes an electrical conductor includes a compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6. 
     
     
       22. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer on a semiconductor substrate;  
       an first passivation layer on the first conductive layer;  
       a dielectric layer on the first passivation layer;  
       a second passivation layer on the dielectric layer; and  
       a second conductive layer on the second passivation layer; wherein at least one of said first and second passivation layers constitutes an electrical conductor.  
     
     
       23. The capacitor structure of claim  22 , wherein the first and second passivation layers include at least one compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6, and at least one of said first and second passivation layers including said at least one compound constitutes an electrical conductor. 
     
     
       24. The capacitor structure of claim  18 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus. 
     
     
       25. A capacitor structure for a semiconductor device, comprising: 
       a first conductive layer over a semiconductor substrate;  
       a first passivation layer over the first conductive layer;  
       a first dielectric layer over the first passivation layer;  
       a second passivation layer over the first dielectric layer;  
       a second dielectric layer over the second passivation layer;  
       a third passivation layer over the second dielectric layer; and  
       a second conductive layer over the third passivation layer, wherein at least one of said first, second and third passivation layers constitutes an electrical conductor.  
     
     
       26. The capacitor structure of claim  25 , wherein at least one the first, second, and third passivation layers include at least one compound having a formula selected from the group consisting of M(O) y X z , M(O) y X z W n , M x X y , and combinations thereof, wherein M is any species present in the dielectric layer other than oxygen or nitrogen, and wherein X and W are selected form the group consisting of nitrogen, fluorine, carbon, chlorine, iodine, and CO 3 , and n, x, y and z are integers from 1 to 6, and at least one of said first, second and third passivation layers including said at least one compound constitutes an electrical conductor. 
     
     
       27. The capacitor structure of claim  26 , wherein M is selected from the group consisting of silicon, tantalum, strontium titanate, barium strontium titanate, boron, boron phosphate, and phosphorus.